© 2017 IADIS Press. The Information Technology Infrastructure Library (ITIL) is the de facto standard framework for providing guidance to IT service delivery and support processes. The ITIL framework has a life cycle of five stages covering the implementation of an IT service. Service transition is the last stage in a project lifecycle before the IT service goes live. This place in the lifecycle is critical, because the success of the project depends on the smooth transition into service operation. This exploratory research investigates the best practices of ITIL service transition stage implementation. IT experts from five case studies have been interviewed to identify challenges and have recommended the best practices that can be used for successful service transition implementation.